Download - New NAD83(2011) Adjustment...1 New NAD83(2011) Adjustment MSPS Annual Conference February 15-17, 2012 David Zenk NGS Advisor A Brief History of Time in MN • Reveal the development

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New NAD83(2011) Adjustment

MSPS Annual ConferenceFebruary 15-17, 2012

David ZenkNGS Advisor

A Brief History of Time in MN

• Reveal the development of the physical Geodetic Control Placement in MN from 1860 through 2007.

• Outline the historical Datums and Adjustments used over time.

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The Big Picture

The Great Depression

The War Years

The Interstate Years

The Modern Era

The HARN

The Big Picture• Total = 59408• Good = 39641, Destroyed = 12944, Other Cond = 6823

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Sample Legend

Marks Set in the 2000 DecadeContributors of Geodetic Control Data and number of marks

! National Agencies

" Inter-State or Inter Province Agencies

# State, Province, Commonwealth, and Territorial Agencies

X County Agencies

[ Other Agencies

1860-1869

• 3 marks• Old set dates are uncertain

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1870-1879

• 11 marks• US Lake Survey• Army Corps

1880-1889

• 55 marks• Army Corps• Miss River Comm• and unknowns

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1890-1899

• The MRC has been busy• Army Corps too

1900-1909

• Closely spaced dots are level lines

• Scattered dots represent triangulation arcs

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1910-1919

• International Boundary Commission

1920-1929

• Connecting the 1890-1909 triangulation to extensive Triangulation across southern MN

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1930-1939

• Great Depression• WPA and CCC make a

contribution to geodetic leveling

1940-1949

• Pre-War– Continuation of

WPA/CCC leveling• Post-War

– US Geological Survey begins benchmark leveling campaign to support Quadrangle Mapping

• Built on existing leveling lines from the 1930’s

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1950-1959

• US Geological Survey expands benchmark leveling campaign to support Quadrangle Mapping

1960-1969

• US Geological Survey expands benchmark leveling campaign to support Quadrangle Mapping

• MHD begins Interstate surveys

• MHD Geodetic Unit started

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1970-1979

• State Highway corridors benefit from geodetic horizontal and vertical surveys

1980-1989


• Metro Area County GPS Surveys

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1990-1999


• County GPS Surveys expand

2000-2007

• County GPS Surveys expand

• Lots of leveling still occurring

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1860-2007

• Cumulative Effort Pays Off!

Historical Datums in MN

• Horizontal– United States Standard Datum of 1913,

• North American Datum, just NAD, not NAD13!

– North American Datum of 1927• NAD27 – almost same datum, new adjustment

– North American Datum of 1983• NAD83 – new datum, several adjustments

– 1986, 1996, 2007

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Sample Datum/Adjustment Shifts

TUCKY MNDT Nicollet County Coordinates (meters)

Datum Tag Easting E Shift Northing N ShiftNAD27 n/a n/a

n/a n/aNAD83(1986) 176327.286 82099.219

-0.026 -0.109NAD83(1996) 176327.312 82099.328

0.012 -0.015NAD83(2007) 176327.300 82099.343


ANTRIM MNDT

Datum Tag Longitude Lon Shift (m) Latitude Lat Shift (m)NAD27 94 26 33.36931 43 52 36.98645

26.357 -3.232NAD83(1986) 94 26 34.22535 43 52 36.83501

0.137 0.057NAD83(1996) 94 26 34.22980 43 52 36.83769

0.010 0.014NAD83(2007) 94 26 34.23013 43 52 36.83833

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APGAR MNDT

Datum Tag Longitude Lon Shift (m) Latitude Lat Shift (m)NAD27 93 31 49.11572 44 47 03.08770

25.631 -2.836NAD83(1986) 93 31 49.94811 44 47 02.95481

0.031 0.111NAD83(1996) 93 31 49.94913 44 47 02.96001

n/a n/aNAD83(2007) not GPS not GPS

Historical Datums in MN • Shifts from NAD27 to NAD83

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• Vertical– Great Lakes Datums

• USLS1903, USLS1935, IGLD1955, IGLD1985– Mississippi River Datums

• Cairo, Memphis, Mean Gulf Level, others– St Paul City Datum (-694.28 ft)– Minneapolis City Datum (-710.48 ft)– National Geodetic Vertical Datum of 1929 (NGVD29)– North American Vertical Datum of 1988 (NAVD88)


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General Relationships Among Vertical Datums


• National Height Modernization– GPS + GEOID = ORTHOMETRIC HEIGHT

• 3D Datum of 2022– Is this the Future?– If everything is moving, what does a datum mean?– Is there anything that’s not moving?

• WANT MORE DETAIL?– http://www.olmweb.dot.state.mn.us– Technology and Tools – then download:

• 2007 Adjustment of the National Spatial Reference System in Minnesota

• Geodetic History in MN

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Datum Conversion Tools

• HORIZONTAL Conversion Tools– NADCON - NGS converter from NAD27 to NAD83– MNCON – MNDOT written conversion tool– CONAD – DOS program from MNDOT, use MNCON now

• VERTICAL Conversion Tools– VERTCON - NGS converter from NAD27 to NAD83

• Combined Conversion Tools– CORPSCON – US Army Corps of Engineers

• Combines NADCON and VERTCON

MNCON

http://www.olmweb.dot.state.mn.us/tech/OlmSoftware.html#MCN

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MN Map Projections and Parameters

http://www.olmweb.dot.state.mn.us/tech/Projections.htm


• NAD83(1986) Original realization – Consisted (almost) entirely of classical (optical)

observations• NAD83(1996)

– “High Precision Geodetic Network” (HPGN) and High Accuracy Reference Network” (HARN) realizations

– Most done in 1990s, essentially state-by-state– Based on GNSS but classical stations included in

adjustments

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• NAD83(2007) National Re-Adjustment of 2007– Used NAD 83(CORS96) epoch 2002.0 as

constraint– Simultaneous nationwide adjustment (GNSS

only)• Needed badly to resolve the state-by-state biases

of the “HARN” era adjustments.• Underlying CORS coordinates were known to be

less-than-perfect, but the Multi-Year CORS Solution (MYCS) was not even close to completed.


• Completion of MYCS in 2011 made a set of constraints available that could truly be described as: “state-of-the art”– Reprocessed all CORS GPS data 1994-2011– 2264 CORS & other global GPS tracking stations– New orbits were computed for all satellites for

all years.– The X,Y,Z and Vx,Vy,Vz for every CORS was

solved for as unknowns in a set of millions of equations

– Accurate computed velocities and consistent coordinates for all CORS

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• Using the MYCS coordinates and velocities as constraints – the new adjustment could include:– 4196 projects – 80,077 stations – 430,766 vectors total – approx 387,000 enabled

• New realization: NAD 83(2011) epoch 2010.00


• Build up of network over time

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NA2011 CONUS 1983-1988 (6 yrs) 7712 vectors (1.8%)

NA2011 CONUS 1983-1992 (10 yrs) 61,574 vectors (14.4%)

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• NAD 83(CORS96) epoch 2002.00 NAD 83(2011) epoch 2010.00

• Expect overall coordinate change about same as MYCS– Horizontal: Mean ~2 cm (±8 cm), median ~0 cm– Vertical: Mean ~ -1 cm (±2 cm), median ~ -1 cm– This is for change in realization and reference epoch

• In MINNESOTA, the changes are about – Horizontal: about 2 cm– Vertical: about 2-3 cm

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• Changes in Ellipsoid Heights mean that a new GEOID Model will be needed.

• New hybrid geoid model (GEOID12)– Use NAD 83(2011) epoch 2010.00 ellipsoid

heights on NAVD 88 benchmarks– Might also use OPUS-Database results on NAVD

88 BMs– Plan release same time as NA2011


• Multi-Year CORS Solution– Officially released coordinates September 2011

• National Adjustment of 2011– Goal: Complete by mid-April 2012– Deadline for submitted projects was Aug 31, 2011

• OPUS (Online Positioning User Service)– Provides solutions referenced both to previous

(CORS96) and new (MYCS) coordinates– Dual solutions will be available until NA2011

complete

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Future Datum

• NGS is planning to release an all-new 3D datum• Timeline not definite.• Consider 10 years away.

New geometric datum minus NAD 83 (horizontal)

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New geometric datum minus NAD 83

(ellipsoid height)

Download - New NAD83(2011) Adjustment...1 New NAD83(2011) Adjustment MSPS Annual Conference February 15-17, 2012 David Zenk NGS Advisor A Brief History of Time in MN • Reveal the development

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